Unit 2 Rocks: Note 5 Erosion

Erosion: the removal and transport of Earth’s surface materials by moving water, air, or ice

Types of Erosion: water, wind, gravity, human activity

Sediment Grains & Erosion: the size, shape, and assortment of sediment grain can help determine what kind of erosion the rock went through

1. Size of grain: can determine how much erosion occurred

   • the smaller the grain the more erosion; the larger the grain the less erosion

   • the smaller the grain the more likely it travelled far; the larger the grain the less likely it travelled far

2. Shape of grain: can determine how much erosion occurred

   • the more rounded the grain the more erosion (transport); the more angular the grain the more erosion (transport)

3. Assortment of grain: can determine how the rock was eroded

   • well sorted grains point to a low transportation energy, like water or wind

   • poorly sorted grains point to a high transportation energy, like glaciers or gravity